Too often the general public relegates mental illnesses like depression, bipolar disorder, and schizophrenia to just that, mental illness, diseases of the mind. However, with modern science, we are beginning to see more and more the folly of this simplistic viewpoint. We are now seeing the science behind these illnesses; the changes in brain form, function, and chemical balance that alter how our brain functions and perceives the world around us. In the “Exploring the Science of…” mini series, I will be talking about how what happens in our brain impacts what happens in our mind.
In this, the last of the “Exploring the Science of…” miniseries, I will be talking about schizophrenia, perhaps the most studied and scrutinized of all mental illnesses.
What is Schizophrenia?
Schizophrenia is a complex brain disorder that affects everything from perception to cognition. Symptoms vary, but include positive, negative, and cognitive symptoms. Positive symptoms are things added on by the disease, such as hallucinations and delusions. Negative symptoms are characters or traits removed by the disease, such as facial expression and enjoyment of activities, both of which can be hindered by schizophrenia. Finally, cognitive symptoms affect the persons ability to think, for example, people with schizophrenia may be unable to concentrate or organize their thoughts the way healthy people can. For more on schizophrenia itself, feel free to check out my post “Understanding Schizphrenia” here.
One very noticeable difference between healthy individuals and those with schizophrenia occurs in the region of the brain called the ventricles. Ventricles are fluid filled cavities in our brain where no actual brain matter is found. However, in some people with schizophrenia, these ventricles are not of a normal size. Instead, they are enlarged. Scientists are not quite sure what that means in terms of cause yet, but are in the midst of studying the phenomena to learn more about what it could mean.
Perhaps the most stark change that happens in schizophrenia occurs in our grey matter, the stuff we use to think. In some individuals with schizophrenia, there are subtle, yet concrete, differences in the amount of grey matter in the brain. Loss can be extreme, in some cases up to 25% of grey matter is lost. Furthermore, the more grey matter is lost, the more severe the schizophrenia. Scientists believe that some symptoms, such as some individual’s lack of awareness of their illness, may be caused by this loss of brain matter and the effect that loss has on cognition. Untreated schizophrenia can result in loss of grey matter, but the good news is that there may be a solution. Some scientists now believe that the loss of grey matter may be reversible with treatment, and that is great news for those with the disease.
Just Think About It
It doesn’t stop at grey matter and ventricles either, that’s just the beginning. Individuals with schizophrenia also show differences in activity levels in different regions of the brain. One of these regions is the prefrontal cortex, a part of the brain reserved for organization and self evaluation, both areas of deficit in schizophrenia. The prefrontal cortex in those with schizophrenia is less active than in healthy subjects. This difference helps to explain why we see some of the symptoms we do.
Auditory hallucinations, or “voices” and other noises, are by far the most common form of hallucination found in schizophrenia, and are experienced by approximately 75% of those with the illness. As someone who suffers from prodromal schizophrenia, the early stage of the disease, the voices were always the most interesting and horrifying part of my symptoms. But far more interesting are the mechanics behind those “voices”, or auditory hallucinations.
When we hear a sound, a region in our brain called the temporal gyrus activates. The temporal gyrus is responsible for handling external audio, makes sense right? That’s not interesting though; here’s what is. When someone experiences auditory hallucinations, that same region of the brain activates, just as if the person were hearing a real voice. More than that, scientists have found that people with schizophrenia also lose brain matter in the temporal gyrus, and the more brain matter lost, the worse the hallucinations.
Like the other diseases we’ve talked about in the “Exploring the Science of…” series, neurotransmitters are again implicated in this disorder. Like most disorders it’s difficult to know exactly what is going wrong with these transmitters; we just know they are causing a problem. Two of the neurotransmitters involved in schizophrenia are dopamine and glutamate.
Dopamine is a very important neurotransmitter which has a variety of functions, the most prominent of which is its role as a “reward” neurotransmitter. You know that feeling you get when you win a game or get something you’ve always wanted? Dopamine. Most all antipsychotics work by blocking dopamine receptors to effectively reduce dopamine levels in the brain, which more often than not helps to alleviate symptoms.
Glutamate is more boring, but also extremely important. It is involved in just about every aspect of our brain and central nervous system, so it’s not to be overlooked. We don’t know why or in what exact way these neurotransmitters are related to schizophrenia, all that we know is that they are.
This article is very near and dear to my heart, since I myself suffer from prodromal schizophrenia, the early stage of the disease. Given my diagnosis, I have about a 50/50 chance of developing the disease that I’ve already shown you can have such disastrous effects on the brain and mind. The good news for myself and so many others is that treatments and drugs for schizophrenia are constantly improving, in no small part because of research such as that which I’ve shown you in this article. As for the causes, effects, and treatments of schizophrenia, for all we know there is much more still to be discovered…